1. Field of the Invention
This invention relates to compositions and processes that are useful for lubricating the surfaces of metals, especially aluminum, copper, and/or most particularly steel, before and during cold forming operations, particularly cold drawing operations. The metal surfaces may or may not have other surface layers such as phosphate conversion coatings; anodized coatings; complex oxide layers such as those that can be formed with a commercially available product named BONDERITE.RTM. 770X from the Parker Amchem Div. of Henkel Corp., Madison Heights, Mich.; or the like underlying the lubricant coating produced on the surface by using this invention. The invention also relates to processes utilizing such compositions.
2. Statement of Related Art
The most widely used lubricants for steel cold forming operations now are believed to be stearate soaps applied over heavy zinc phosphate conversion coating layers. These produce satisfactory drawing results, but are susceptible to dusting, which can become a severe nuisance to workers during the drawing operations. Stearates also often result in the generation of substantial volumes of sludge, which can become an expensive disposal problem. Furthermore, the phosphate conversion coatings usually contain heavy metals such as nickel, manganese, or calcium in addition to zinc in order to achieve the best drawing results, and such metals may cause pollution problems in disposal. It is an object of this invention to provide alternative lubricants with at least equally acceptable performance during the drawing operation and less disposal, or other environmental, problems.